I don't feel these are the effects from surgery.
I have read your query. At this outset, I would first rule out circulatory disturnbances. It can be the cause of pain and color changes of toes. It is unlikely due to past hip surgeries.
I would recommend that you report back to the surgeon. He/she should examine you and then order for color doppler of both limbs
. He may also order for X-ray lumbosacral spine in AP and Lateral view, xray of pelvis with both hips. I expect your doctors to get to the root after the problem via these basic investigations.
Till then you can take some painkillers like aceclofenac
and apply hot packs at lower back and affected foot.
Avoid weight lifting , pushing and pulling heavy weights.
I hope you have got your answer.